code: def passthrough(x):
      return x
  
file_path: hyperopt/hyperopt/tests/unit/test_anneal.py
imports: from functools import partial
  import unittest
  import numpy
  from hyperopt import anneal
  from hyperopt import rand
  from hyperopt import Trials, fmin
  from .test_domains import CasePerDomain
label_desc: Use image node_id 1 for calling a global function with example usage: passthrough(x) and returns: x